Fix "Replace !! with if-then" inspection in receiver position

#KT-5412 Fixed

idea/testData/intentions/branched/doubleBangToIfThen/replaceParentExpression.kt

@@ -0,0 +1,15 @@
+// WITH_RUNTIME
+fun foo(): String? {
+    return "foo"
+}
+
+class A {
+    fun f(): Int {
+        return 42
+    }
+}
+
+fun main(args: Array<String>) {
+    val a: A? = A()
+    a<caret>!!.f()
+}

idea/testData/intentions/branched/doubleBangToIfThen/replaceParentExpression.kt.after

@@ -0,0 +1,15 @@
+// WITH_RUNTIME
+fun foo(): String? {
+    return "foo"
+}
+
+class A {
+    fun f(): Int {
+        return 42
+    }
+}
+
+fun main(args: Array<String>) {
+    val a: A? = A()
+    if (a != null) a.f() else throw NullPointerException("Expression 'a' must not be null")
+}

idea/testData/intentions/branched/doubleBangToIfThen/replaceParentExpression2.kt

@@ -0,0 +1,16 @@
+// WITH_RUNTIME
+fun foo(): String? {
+    return "foo"
+}
+
+class A {
+    val g = 44
+    fun f(): Int {
+        return 42
+    }
+}
+
+fun main(args: Array<String>) {
+    val a: A? = A()
+    a<caret>!!.g
+}

idea/testData/intentions/branched/doubleBangToIfThen/replaceParentExpression2.kt.after

@@ -0,0 +1,16 @@
+// WITH_RUNTIME
+fun foo(): String? {
+    return "foo"
+}
+
+class A {
+    val g = 44
+    fun f(): Int {
+        return 42
+    }
+}
+
+fun main(args: Array<String>) {
+    val a: A? = A()
+    if (a != null) a.g else throw NullPointerException("Expression 'a' must not be null")
+}

idea/testData/intentions/branched/doubleBangToIfThen/replaceParentExpression3.kt

@@ -0,0 +1,15 @@
+// WITH_RUNTIME
+fun foo(): String? {
+    return "foo"
+}
+
+class A {
+    fun f(): Int {
+        return 42
+    }
+}
+
+fun main(args: Array<String>) {
+    val a: A? = A()
+    val b = a<caret>!!.f()
+}

idea/testData/intentions/branched/doubleBangToIfThen/replaceParentExpression3.kt.after

@@ -0,0 +1,15 @@
+// WITH_RUNTIME
+fun foo(): String? {
+    return "foo"
+}
+
+class A {
+    fun f(): Int {
+        return 42
+    }
+}
+
+fun main(args: Array<String>) {
+    val a: A? = A()
+    val b = if (a != null) a.f() else throw NullPointerException("Expression 'a' must not be null")
+}